Misfiring-testing device for multiple-cylinder engines.



' abnormal conditions. f 85 MATT B. THURBER, or" TECUMSEH, NEBRASKA.

MISFIRING-TESTING DEVICE FOR MULTIPLE-CYLINDER ENGINES.

Specification of Letters Patent.

Patented Sept. 17 1918.

Application filed October 21, 1914. Serial No. 867,788. 1

To all whom it may concern:

Be it known'that I, MATT B. THURBER, a citizen of the United States, and a resident of Tecumseh, in the county of Johnson and State of Nebraska, have invented a new and Improved Misfirin -Testing Device for Multiple-Cylinder ngines, of which the following-is a full, clear, and exact description.

This invention relates to a testing device for ascertaining which cylinder or cylinders of a'multiple cylinder engine is or are misfiring, being due't'o a variety of causes, such as a fouled spark plug; failure of the current to reach the spark plug because of an open or grounded circuit; failure of compression due to leaky valves, piston rings or other leaks"; improper mixture of gas with air, due to the leak in the intake manifold, etc.

The invention has for its general objects to provide a device which is easily and quickly applied to the engine when any cylinder or cylinders fail to operate efliciently,.to determine which cylinder is affected, the device being of such a nature that it is applied to the insulated electrodes of the spark plugs in all the cylinders except the cylinder to be tested, and also connected with the body of the engine so that as the engine is operated the cylinder to be tested will fail to ignite if the spark plug thereof is not operating properl v or because of other the spark plug or cylinder is in proper condition the charge of mixture will of course explode and show that the cylinder is not affected. Another cylinder is then. selected to be tested by de taching the thereof and attaching it to the plug of the cylinder previously tested, so that allof the spark plugs, except the new cylinder that is to be tested, will 'be grounded, and.

when the engine s again started or cranked the condition of the second cylinder will be determined by the fact that the charge fails to fire, or fires with a weak or normal impulse.

More specifically the object of the inven tion is to provide a gas enginecylinder testing device whi h comprises a plurality of connected or grounded wires which c0rre-' the number of cylinders spend in number to in the engine with whlch the device is used, and each wire is provided with a clip whereby it can be easily and quickly connected engine for testing thereof;

'anengine device from the spark plug with the insulated-electrodes of the. spark plugs and with a priming cup or other groundlng part, whereby simultaneously all of the spark plugs except one can be grounded, so that in the ignition system there will be only one spark plug which will not beshort circuite'd, and the condition of this plug or the cylinder containing it will be determined by its ability or inability to fire the charge in the cylinder toiwhich it is attached. Y Z

With such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will beset, forth with particularity in the following description and claims appended hereto. 7

In the accompanying drawing, which illustrates. one embodiment of the invention, and wherein similar characters of reference indicate corresponding parts in all the views,

Figure 1 is a perspective view of the testing device shown applied to a four-cylinder one of the cylinders Fig. 2 is an enlarged sectional view of the clip on the free end of each wire of the de- Fig-. 3 is a sectional view of the handle of the device, showing the common connection for the several wires.

' In the present instance the testing device is shown with four wires 10, 11, 12 and 13, so that it can be used with an engine having .two, three or four cylinders, but with ders more-wires are required, as the device must have at least as many wires asthere are cylinders in the engine to be tested. The wires are covered with insulation 14 and no parts are exposed except the attaching.

clips, so that there is no danger of the user receiving shocks. The wires at one end are fastened in a socket 14; of a handle 15 made of insulating material, and the several wires are connectedor grounded at 16 within the handle. On the free end of each wire is a clip 17 formed of oppositely disposed wire members or jaws 18 which have straight shank portions 19 covered by a sleeve 20 of insulation, and within the sleeve, which forms a handle for the clip, the shanks 19 of the two members of the clips are electrically connected at 21 with the metal-conhaving a larger number of cylin ductor of the wire. The clip members 18 are so constructed that they can be easily to form'the jaws proper which gripthe outer extremities of. the spark plugs on the priming cups or the like.

In ,usingthe device no 1 alterations are made theignltlon-system-A, as by changmg the regular wiring or disconnect-mg any 0 of the'parts, since the object ofthe deviceis merelyv to ground all of the spark plugs'at one time except the one in the cylinder to be tested. Each spark plug has an insulated electrode,"and it is therefore merely necessary to attach the clips 17 to the nuts on' the outer endsfof the insulated electrodes and attach one of the wires tofthe body of the engine, as for instance, by snapping the clip of such wire on a priming cup. This application of the device isvshown in Figfihwhere some other cylinder'needs to betested, and

'bile orshung up in the garage.

the wire 10 is attached to a-ipriming cupr24 and the. wires 11, 12 and 1'3 are attached to the spark plugs 25 of the cylinders 1, 2 and 3, whereby the device willvenable cylinder 'inga plurality of flexible conductors elec- 4: to be tested. Ifcylinder 4 is misfiring the engine will of course stop as soon as the testing device is applied to the engine as 'described, but if the mixture in cylinder 41 continues to explode. the user will know that accordinglythe wire 13 will be detached frnm the spark plug of cyliinderB and at.

tached to the spark plug of cylinder 4, so that all the other spark plugs but-that of cylinder 3 will be grounded, and when the engine is operated the condition of this spark plug will be determined. Y'Inthis manner the spark plugs of the various cylinders} are tested. Obviously thedevice is only used when the operator is aware'offone "or' more of the spark plugs being out of order, and whennot in use the device. isp

either carried'in the toolkit of theautomo- From the foregoing description-taken..in connection withthe accompanying drawing,

the advantages .of the construction and ahandle for the clip.

method of operation willbe readily understood by those skilled in the art to which the inventionappertains, and while I have described the principle of operation, together with the device which I now consider to be the best embodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may be Inadewhen desired as are within the scope of the appended claims Having thus described my invention, I claim asnew and desire to secure by Letters Patent: Y

1'. A. testing tool adapted to'be appliedto the spark plugs of a multiple cylinder'engine and normally disconnected therefrom, said tool comprising a pluralityof flexible conductors, a handlein which all of the con ductors are. anchored and electrically connected togethenand attaching clips on the outer extremities of the conductors.

2. As an article of manufacture, a testing device of the class described comprising a plurality of flexible conductors electrically connected, a clip composedof wire members connected with eachconductor, and a sleeye on each conductor and in which the clip thereof is fastened, whereby the sleeve forms 3. A device of the class described compristrically connected, a'clip composed of wire members connected with each conductor, a

sleeve on each conductor and in which the clip thereof isfastened, whereby the sleeve 4; A testing tool adaptedto gum and normally disconnected therefrom, said tool comprising a plurality of flexible conductors, a support to which all of the jconductors are anchored and electrically connected together, and attaching clips on the outer extremities of the conductors In testimony'whereof I have signed my p be applied to the spark plugs of a multiple cylinder enname to this specification in thepresence of two subscribing witnesses.

- MATT B. TH-URBER.

Vt itnesses FRANK L. DINsMoRn, EMMA M. MADDEN. 

